Good to do or bad?

Five year old boy from Phil of Rhineland-Palatinate really missed his grandfather. "He again and again began to remember my grandfather and could not accept to come to terms with his death," says his mother. Then the boy's parents came up with the idea to write grandpa a letter and send it with a balloon.
The letter, which Phil asked grandpa whether he is in heaven and is there with him, obviously really found its destination. After some time it came to the parcel. In the package was a Teddy bear, and the following letter:
"Dear Phil,
your balloon flew so high, flew to me in heaven. I was lucky to catch it. I am sending you this Teddy bear. He will comfort you when you sad. Don't worry about me. I'm fine, though I miss you very much.
With love, your grandfather"
"Unfortunately the parcel was no sender name, no return address. But the postmark was clear that the parcel was sent out of the land of Nordrhein-Westfallen," says the boy's mother. "Phil cried tears of joy when I read the letter to him. On the death of his grandfather he no longer speaks. And the bear he now always carries with him.


What will be the reaction of the boy when he grows up and realizes that he had been deceived?
Is it good to do with your child or bad?